Conventionally, acoustic stethoscopes have been used for auscultation (i.e., listening to internal sounds originating from within a body). Acoustic stethoscopes often include a single chestpiece having a resonator designed to be placed against the body and a pair of hollow, air-filled tubes that are connected to earpieces. As acoustic sound waves are captured by the resonator, they are directed to the earpieces via the pair of hollow, air-filled tubes.
But acoustic stethoscopes suffer from several drawbacks. For example, an acoustic stethoscope attenuates the acoustic sound waves proportional to the frequency of the source. Thus, the sound conveyed to the earpieces is often very faint, which can make it difficult to accurately diagnose a condition. In fact, due to the variation in sensitivity of the ear, some sounds (e.g., those below 50 hertz (Hz)) may not be heard at all. Some enterprises have begun developing electronic stethoscopes (also referred to as “stethophones”) to address the drawbacks of acoustic stethoscopes.
Electronic stethoscopes improve upon acoustic stethoscopes by electronically amplifying sounds heard within a body. For instance, an electronic stethoscope may address the faint sounds originating from within a body under examination by amplifying these sounds. To accomplish this, the electronic stethoscope converts acoustic sound waves received by a microphone placed in the chestpiece into an electrical signal, and then amplifies the electronical signal for optimal listening.
However, amplification may result in undesirable digital artifacts that make it more difficult to diagnose conditions affecting the body. Moreover, component cutoffs (e.g., the frequency response thresholds of microphones, amplifiers, and speakers) may limit electronic stethoscopes' utility by simultaneously amplifying mid-frequency sounds and attenuating high- and low-frequency sounds.
Unlike acoustic stethoscopes, the designs of electronic stethoscopes vary widely. While electronic stethoscopes may include different arrangements of microphones, amplifiers, processors, etc., many electronic stethoscopes include a single downward-facing microphone that is placed within the resonator. But such a design suffers significant interference from ambient noise.
The drawings depict various embodiments for the purpose of illustration only. Those skilled in the art will recognize that alternative embodiments may be employed without departing from the principles of the technology. Accordingly, while specific embodiments are shown in the drawings, the technology is amenable to various modifications.